Apparatus for extracting an element from an assembly

ABSTRACT

A chuck includes a support and a plurality of pairs of oppositely disposed jaws with the jaws being movable to a position with each pair of jaws disposed on diametrically opposite sides of one element of an assembly. A motor moves selected pairs of the jaws into contact with the element and an additional motor moves the selected pairs of jaws and element away from the support to extract the element while at least one of the pairs of oppositely disposed jaws are maintained in position on the support to secure a second element of the assembly against movement while the selected pairs of jaws extract the one element.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to apparatus for extracting an elementfrom an assembly useful in the manufacture and repair of tubularproducts and, more specifically, to apparatus for extracting an elementfrom a tubular member as required during disassembly of an automotivedrive shaft.

Automotive drive shafts sometimes referred to as drive lines arecomprised of a tubular member having an element such as a yoke of auniversal joint, a bearing stub or one component of a slip joint fittedat each end thereof. Such elements are usually pressed into the hollowinterior of the tubular member and secured by a circumferential weldjoint effected between the end of the tubular member and a surface ofthe inserted element.

In automotive applications, drive shafts are utilized, either singularlyor in combination, as a torque transmitting component(s) of the powertrain and are most commonly located under the vehicle between thetransmission or other gear box and the differential of a drive axle. Theends of the drive shaft are usually connected to other components of thepower train by a yoke which is fitted to one end of the drive shaft andconnected by means of a universal joint cross shaped journal to anotheryoke receiving or delivering torque from or to an adjacent component ofthe power train.

Torque transmitting drive shafts of this type, especially when employedon commercial vehicles and heavy duty trucks, are subject to suddenchanges in torque and exposed to road hazards which, during the life ofthe vehicle, may cause wear or damage to the drive shaft. In the eventof such wear or damage, the drive shaft may be removed and replaced inits entirely which is rather expensive. Depending upon the nature of thewear and/or damage incurred, the drive shafts may also be disassembledand repaired which is less expensive than replacing the unit, however,this option depends upon the availability of equipment necessary todisassemble and reassemble the drive shaft assembly.

2. Description of the Prior Art.

Various types of machinery and equipment such as lathes, vises, presses,cutting tools and welding devices have been employed to repair driveshafts in the past. These are general purpose devices and have usuallybeen used to perform only a single function in the assembly and/ordisassembly of driveshafts. Some of the equipment, for example, lathesand presses, are relatively expensive when used to perform only a singlefunction. The assembly and disassembly of drive lines has also requiredhigh labor costs since the work pieces have traditionally been movedfrom one machine to another for each sequential operation and the driveshafts, some of which may be ten to twelve feet long, have to be set upfor each separate operation.

One machine developed specifically for working an automotive driveshafts is disclosed in U.S. Pat. No. 3,758,098. That machine is similarto a lathe having a head stock and movable tail stock mounted to arelatively long support bed. The drive shaft is mounted between the tailstock and the head stock which includes a hydraulic jack. The machinedisclosed by U.S. Pat. No. 3,758,098 requires an adaptor in the form ofa U-joint yoke, a U-joint cross and a yoke on the drive shaft to mountthe drive shaft or work piece in the machine. The machine is alsorelatively long and cumbersome considering that work is usuallyperformed at only one end of the drive shaft at any one time.

The present invention avoids many of the problems encountered whenattempting to disassemble and repair tubular articles such as automotivedrive shafts by providing apparatus in the form of a chuck having aplurality of jaws some of which abut and prevent movement of the end ofthe tubular element while other jaws engage and pull the element fromthe interior of the tubular member.

SUMMARY OF THE INVENTION

The present invention provides an apparatus for extracting an elementfrom an assembly comprising chuck means including a support and aplurality of pairs of oppositely disposed jaws with the jaws beingmovable to a position with each pair of jaws disposed on diametricallyopposite sides of at least one element of the assembly. A motor movesselected pairs of the jaws into contact with the element and additionalpower means moves the selected pairs of jaws and element away from thesupport. Means are also provided for maintaining at least one of thepairs of oppositely disposed jaws in position on the support whereby theone pair of jaws secures a second element of the assembly againstmovement while the selected pairs of jaws move the one element relativeto the second element. The support is preferably comprised of anassembly of a pair of rails secured in spaced parallel relation, a pairof blocks carried by the rails and at least one of the blocks is movablealong the rails relative to the other block.

In the preferred embodiment the rails are secured at one end to asupport bar and at the other end to one of the blocks. A jaw plate andat least one additional jaw element are carried by each of the blocks.Means are also provided for moving each of the jaw plates in a directionnormal to its respective block and maintaining each of the additionaljaw elements adjacent its respective block.

In the preferred embodiment each of the blocks also support a pluralityof guide rods projecting normal to a major surface of the block and eachjaw plate has a plurality of apertures receiving the guide rodssupported by its respective block and slidably mounting the jaw platefor reciprocating movement toward and away from that block.

The additional jaw element supported by each block is mounted forreciprocating movement in a direction substantially normal to thedirection of movement of the jaw plates and the additional jaw elementsare prevented from moving with the jaw plates.

The jaw plates are also biased toward their respective blocks.

These and other features and advantages of the invention will becomeapparent from the following detailed description of the embodiment shownby the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, wherein like reference numerals refer to like parts,

FIG. 1 is a side view, partly in section of the apparatus according tothe present invention;

FIG. 2 is a plan view of the apparatus of FIG. 1;

FIG. 3 is a side view showing certain elements of FIG. 1 in greaterdetail;

FIG. 4 is a plan view of the elements shown in FIG. 3;

FIG. 5 is a front view of a sub-assembly of the apparatus shown by FIGS.1 and 2;

FIG. 6 is a plan view of the assembly of FIG. 5;

FIG. 7 is an enlarged partial end view in certain elements of theassembly of FIGS. 5 and 6 in greater detail;

FIG. 8 is a front view of an element of the assembly of FIG. 5;

FIG. 9 is an end view of the element shown by FIG. 8;

FIG. 10 is a partial view showing the end structure of the elments ofFIGS. 8 and 9;

FIG. 11 is a front view of an additional element of the assembly of FIG.5;

FIG. 12 is an end view of the element of FIG. 11 and

FIG. 13 is an enlarged partial view showing details of the shape at oneend of the element of FIG. 11.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to the drawings, FIGS. 1 and 2 in particular, there isshown a frame 8 comprised of a plurality of legs 10 and an elongatesupport bed 11. A housing 12 secured to the support bed 11 rotatablymounts a multiple jaw chuck 14 which is a first chuck means 15 onbearings 16 and 18 for rotation about a horizontal axis 19. Rotarymovement of the sleeve 15 and multiple jaw chuck 14 is provided by meansof a sheath 20 secured to the sleeve 15 and receiving a pair of V-belts21 driven by motor 22. The multiple jaw chuck 14 includes a plurality ofjaws 13, three are employed in the preferred embodiment and are spacedequidistantly around horizontal axis 19. The space between the jaws 13and the hollow cylindrical sleeve 15 provides a generally cylindricalpassage 24 for receiving the work piece such as, for example, a hollowtubular drive shaft 25.

A pedestal 2 remote from the frame 11 supports one end of a pair ofcylindrical stringers 3 which are secured at their opposite ends to thehousing 12. The stringers 3 slidably mount a workpiece support bar 4.The support bar 4 can be selectively positioned at various locationsalong the stringers 3 by means of a pair of pins 6 which engage aselected pair of a plurality of holes 7 provided diametrically throughthe stringers 3. The support bar 4 is threaded at a central locationaligned with the horizontal axis 19 and serves as a nut for hand crankoperated power screw 5 having a plate 9 for supporting the remote end ofthe driveshaft workpiece 25.

The plate 9 can be adjusted to support the remote end of any tubularworkpiece within the limits of the length of stringers 3 by moving thesupport bar 4 to the appropriate pair of holes 7 and adjusting thehandcrank and power screw 5 to locate the plate 9 in abutment with theremote end of the workpiece.

An upright stanchion 28 is secured to the end of the support bed 11opposite from the housing 12 and multiple jaw chuck 14. The stanchion 28provides support for an upper frame member 29 secured at its oppositeend to the fabricated housing 12. Frame member 29 also supports threecontrol boxes with actuating levers 33, 87 and 125 for actuating andcontrolling hydraulic cylinders to be described herebelow. The stanchion28 also supports a tool head 30 fixed to the end of a piston 31 of ahydraulic cylinder 32 secured to the stanchion 28. A vise 34 having aplurality of jaws actuated by means of quick release keys 35 is mountedto the tool head 30.

A tool fixture 38 is mounted for movement by means of a first hand wheel39 along a track 40 secured to a horizontal edge of the support bed 11between the multiple jaw chuck 14 and the stanchion 28. The tool fixture38 is also movable laterally across the support bed 11, i.e., toward andaway from the horizontal axis 19 by means of a second hand wheel 41. Thehand wheels 39 and 41 respectively drive power screws arranged formoving the tool fixture carriage and the tool fixture 38 to a desiredwork location in a convention manner.

A bracket 44 secured to the housing 12 is cantelivered to the rear ofthe apparatus as shown by FIG. 1 and by means of a pin 45 pivotallymounts a double swing arm assembly 48.

With reference to FIGS. 3 and 4, the double swing arm assembly 48 iscomprised of a first arm or plate 50 pivotally mounted to a second armor plate 51 by means of a pin 49. The arm 50 is provided with aplurality of bosses 52, one at each corner of the arm 50. Each of thebosses 52 is provided with a bore. The bores in two of the bosses 52 areaxially aligned and slidably received for pivotal movement on the pin45. The bores through the two bosses 52 are axially aligned and slidablyreceived for pivotal movement on pin 49. The arm 51 is provided at oneside with two bosses 54 having bores axially aligned to be slidablyreceived and pivotal about the pin 49. The pins 45 and 49 may be securedagainst axial movement relative to the bosses of the arms 50 and 51 byconventional means, for example, a set screw provided through at leastone of the bosses. A plurality of thrust washers 55 may also be providedbetween adjacent bosses to maintain the desired spacing and provided forsmooth rotation of the arms 50 and 51 relative to the pins 45 and 49.

Plates 56 and 57 are respectively secured by welding at the upper andlower edges of swing arm 51 as viewed in FIG. 3 and provide a bracketpivotally supporting, by means of upper and lower pins 58 and 59, thesupport bar 61 of an additional chuck assembly for holding andextracting opposed elements of an assembly such as a drive shaft asdescribed hereinabove.

The additional chuck assembly 60 which is a second chuck means, as bestshown by FIGS. 5 and 6, is comprised of the support bar 61, a pair ofrods 62 and 64, blocks 65 and 66, jaw plates 68 and 70 and fingers 69and 71. The rods 62 and 64 are secured in spaced apart parallelrelationship in bores 74 and 75 provided to the support bar 61 and boresrespectively provided to boss 76 and boss 78 of block 65. The bore 75 insupport bar 61 is counter sunk and one end of the rod 64 is securedtherein by means of a cap screw 79. The other end of the rod 64 issecured in boss 77 of block 65 by means of a set screw 80 and thecorresponding end of the rod 62 is secured in boss 76 of block 65 byanother set screw 80.

Block 66 is provided with a plurality of bosses 81, one boss at eachcorner of the block, and each of the bosses is provided with a bore 82adapted to be slidably received upon one of the rods 62 or 64. A plate84 secured by a plurality of cap screws to the right hand edge of block66 as viewed in FIGS. 5 and 6 is connected at 85 to the piston 86 of ahydraulic cylinder 88 secured by means of a threaded connection at 89 toa bore provided to the support bar 61. The block 66 is thus mounted forsliding or reciprocating movement along the rods 62 and 64 underactuation of the hydraulic cylinder piston 86. the rods 62 and 64 thusserve as rails guiding reciprocating movement of the block 66 parallelto a plane defined by the longitudinal axes of the rods 62 and 64.

Jaw plates 68 and 70 are respectively mounted to blocks 65 and 66 formovement relative thereto. Blocks 65 and 66 are each provided with pairsof guide rods 90 and 91. The guide rods 90 and 91 are each respectivelyseated and welded to a bore 95 provided in the block 65 or 66 andproject or extend normal to the surface of its respective guide block.Jaw plates 68 and 70 are each provided with four apertures 98 which aredimensioned and located to slidably receive the guide rods 90 and 91.The jaw plates 68 and 70 are thus slidably mounted on the guide rods 90and 91 for movement relative to their respective blocks 65 and 66.

The guide rods 91 are longer than the guide rods 90. Each of the guiderods 91 mount a compression spring 92 seated at one end against thesurface of a jaw plate 65 or 66 and at the other end against a cap screwand washer assembly 94 threaded to the other end of the guide rod 91.The springs 92 thus bias the jaw plates 68 and 70 into position adjacenttheir respective blocks 65 and 66.

As shown by FIG. 8, one end of the jaw plate 70 is cut to provide a pairof obliquely disposed converging edges 102 and 104. The edges 102 and104 converge at an angle of about 120° and are machined to respectivelyprovide very narrow tips 106 and 108 preferably 0.20 inches or less inthickness as viewed in FIG. 10. As shown by FIGS. 8 and 9 a centrallylocated, relatively large diameter bore 109 is provided through thethickness of jaw plate 70 and threaded at 110 for a purpose which willbe described more fully below. A recess or groove 111 is also providedacross the width of jaw plate 70 as shown by FIG. 8. The recess 111extends from the converging edges 102 and 104 through the bore 109 tothe edge of the jaw plate opposite from the converging edges 102 and104.

Jaw plate 68 includes the same elements as just described for jaw plate70 and is identical in structure thereto, the only difference being thatthe jaw plate 68 is mounted in reverse or opposite hand relation to thejaw plate 70 in the additional chuck assembly 60.

The fingers 69 and 71 like the jaw plates 68 and 70 are also ofidentical structure with the finger 69 like the jaw plate 68 beingmounted of opposite hand to the finger 71 in the additional chuckassembly 60. Accordingly, the structure of finger 71 will be describedin detail with reference to FIGS. 11-13 with the understanding that thestructure of finger 69 is identical thereto.

The finger 71 is an elongate element of generally rectangularcross-section having a pair of shoulders 114 and 115 forming a base 116which extends substantially the length of the finger 71. One end of thefinger 71 is cut away to form a relatively narrow rounded tip 118. Thewidth of the tip 118 as shown by FIGS. 12 and 13 is very narrow, andlike the jaw plate tips 106 and 108, preferably less than bout 0.20inches. A bore 119 is provided through the finger 71 adjacent the endopposite the tip 118.

The fingers 69 and 71 are mounted for sliding or reciprocating movementbetween their respective jaw plates 68, 70 and blocks 65, 66. Withreference to FIG. 7 the finger 69 is partly located within the groove111 provided to jaw plate 68 and the base 116 is slidably receivedwithin an undercut recess 124 provided to the block 65. A pin 120 isseated in the bore 119 provided to finger 69. The pin 120 is located ina slot 121 provided through the rear surface of the block 65 therebyrestricting movement of the finger 69 in the groove 111 and undercutrecess 124 to the length of the slot 120. The finger 69 is thus mountedfor limited sliding movement in the slot 111 and undercut recess 124while the pin 120 prevents the finger 69 from being withdrawn fromeither end of the assembly. The finger 71 is mounted in identical mannerbetween a groove 111 provided to the jaw plate 70 and an under cutrecess 124 provided to the block 66 for similar limited reciprocatingmovement. The tips 118 of the fingers 69 and 71 are formed to be invertical alignment with the adjacent jaw plate tips 106 and 108 when thefingers 69 and 71 are assembled to the jaw plate grooves 111.

Hydraulic cylinders 126 and 128 are respectively threaded to the bores109 of jaw plates 68 and 70. The hydraulic cylinders 126 and 128 arearranged with their pistons 127 and 129 acting directly upon the facingsurfaces of block 65 and finger 69 and block 66 and finger 71. Whenfluid pressure is applied to the hydraulic cylinders 126 and 128 theirpistons 127 and 128 seat against their respective blocks and fingerswhile the housing of hydraulic cylinders 126 and 128 move theirrespective jaw plates 68 and 70 along the guide rods 90 and 91 as shownin phantom, at the left side of FIG. 6. When fluid pressure is releasedfrom the cylinders 126 and 128, the biasing springs 92 provided on guiderods 91 move the jaw plates 68 and 70 back into abutment with theirrespective blocks 65 and 66.

The tips 106 and 108 of jaw plates 68 and 70 and the tips 118 of fingers69 and 71 thus provide a plurality of jaws in the additional chuckassembly 60 for gripping and performing certain specified operations ona work piece located concentrically therebetween. For example, withreference to FIG. 5, actuation of hydraulic cylinder 88 will move itspiston 86 and block 66 carrying jaw plate 70 and finger 71 to the leftthereby locating the tips 102 and 104 of jaw plates 68 and 70 and tips118 of fingers 69 and 71 in diametrically opposed concentricrelationship with a tubular work piece as shown by phantom lines in FIG.5.

The operation of the apparatus as it would be utilized to repair atubular article, for example, an automotive drive shaft which may havebeen damaged or subject to excessive wear will now be described.

As received from the field, the drive shaft 25 having a yoke 26 pressfit to the hollow interior of the drive shaft and secured by means of acircumferential weld joint 27 effected between the yoke and one end ofthe drive shaft is secured by the jaws 13 of multiple jaw chuck 14 withthe yoke 26 positioned between the multiple jaw chuck 14 and the vise 34and the other end of the drive shaft abutting the remote support plate9. A cutting tool is secured to the tool fixture 38 and moved intoposition adjacent the weld joint 27. The motor 22 is activated by theswitch 23 to rotate the multiple jaw chuck 14 and the drive shaft 25while the cutting tool is continually advanced by means of the handcrank 41 to engage, cut and remove the weld material from joint 27. Whenthe weld material has been removed from the joint 27, a smallcircumferential groove should remain between the yoke 26 and theadjacent end of the drive shaft 25. The cutting tool and tool fixture 38are then withdrawn from the work area by operation of hand wheels 39 and41.

The additional chuck assembly 60 is then moved into position adjacentthe face of multiple jaw chuck 14. Although the auxiliary chuck assemblyis a relatively heavy apparatus including a plurality of metalcomponents and hydraulic cylinders, the double swing arm assembly 48enables the operator to manually position the assembly 60 in the desiredlocation as shown by phantom lines in FIG. 2 with relatively littleeffort. This is accomplished by grasping the D-shaped handle 63 providedto the outer edge of block 65, swinging the entire assembly until theblock 65 passes in front of the yoke 26 and then pushing rearwardlyuntil the tips 106 and 108 of jaw plate 68 are seated in the groove fromwhich the weld material has been removed. The operator then moves lever87 to actuate hydraulic cylinder 88 which, as shown by phantom lines inFIG. 5, will move block 66, jaw plate 70 and finger 71 to the left untilthe tips 106 and 108 of jaw plate 70 engage the groove where the weldmaterial has been removed from the other side of the drive shaft 25. Theoperator then checks to make certain that the tips 118 of fingers 69 and71 are also positioned in the groove and if not, the fingers are movedmanually into such engagement.

The hydraulic cylinders 126 and 128 are then actuated simultaneously bylever 125 to move the jaw plates 68 and 70 and their respectiveconverging edges 102 and 104 away from their respective blocks 65, 66and fingers 69, 71. The tips 106 and 108 of the converging edges 102 and104 of the jaw plates 68 and 70 are engaged with the yoke 26 andwithdraw the yoke from the interior of the drive shaft 25 as the tips118 of the fingers 68 and 71 engage and secure the adjacent end of thedrive shaft against movement with the yoke 26 as it is being withdrawn.The yoke 26 is then removed from the additional chuck assembly 60 andthe assembly 60 is easily moved by the double swing arm assembly 48 outof the work area to the position shown by solid lines in FIG. 2.

A new or replacement yoke is fitted to the vise 34 and hydrauliccylinder 32 is actuated by lever 33 to press fit the stub of thereplacement yoke to the interior of the tubular drive shaft 25. Acircumferential weld joint is then effected between the yoke and the endof the drive shaft to secure the yoke in place. This may be accomplishedby means of a welding torch or electrode carried by the tool fixture 38,or, if desired, the drive shaft and relacement yoke assembly may beremoved to another work station where the weld would be effected aroundthe joint between the replacement yoke and the adjacent end of the driveshaft.

The invention may also be embodied in other specific forms withoutdeparting from the spirit or essential characteristics thereof. Theforegoing description is therefore to be considered as illustrative andnot restrictive, the scope of the invention being defined by theappended claims, and all changes which come within the meaning and rangeof equivalency of the claims are therefore intended to be embracedthereby.

I claim:
 1. Apparatus for extracting an element from an assemblycomprising:an elongated frame comprising a plurality of elongatedparallel stringer members having spaced bores therein for securing atransverse support bar in said bores to provide a plurality of positionsof said bar with respect to the frame; a transverse support barmechanism transversely positioned and detachably secured to saidstringer members to support a portion of the assembly; a first chuckmeans mountd on said frame which aligns with said support bar mechanismfor holding a portion of the element to be extracted; a tool meanssecured to said frame which is movable longitudinally to and away fromsaid first chuck means and movable transversely to said frame; a visemeans secured to said frame which is longitudinally retractable to holda portion of the element which is to be extracted; an arm assemblyincluding a second chuck means having a pair of jaws which extracts theelement from the assembly being movable both longitudinally and axiallytowards said first chuck means comprising a pair of rails located on theframe for supporting said second chuck means including means securingsaid rails in spaced apart and parallel relation to each other; a pairof blocks supporting the jaws of said second chuck means, said blocksbeing attached to said rails and at least one of said pairs of blocksbeing movable along said rails; and each of said pair of jaws of saidsecond chuck means being secured to a respective one of said pair ofblocks to move with said blocks and to move relative to said blocks in adirection transverse to the movement of said blocks.
 2. Apparatus asclaimed in claim 1 wherein said pair of jaws of said second chuck meansincludes jaw plates and motor means operative between each of the jawplates to move said jaw plates along said rails away from the respectiveblocks.
 3. Apparatus as claimed in claim 2 further comprising additionalmeans operative to prevent the jaws of said second chuck means frommoving with said jaw plates of said second chuck means.
 4. Apparatus asclaimed in claim 3 including means biassing each of said jaw plates ofsaid second chuck means towards its respective block.